1. Field of the Invention
The present invention relates to a slide operation apparatus having a box body thereof in which a movable unit is disposed for movement when an operating element thereof is operated or manipulated, the slide operation apparatus being used for setting the volume or other parameter in a system mounted with the slide operation apparatus.
2. Description of the Related Art
Conventionally, there has been known a slide operation apparatus such as a fader mounted on a mixer or other system. The slide operation apparatus generally includes a box body in which a movable unit is disposed for movement. The movable unit can be moved, for example, by a user by grasping and manually operating an operating element fixed to the movable unit. The mixer or the like mounted with the slide operation apparatus detects the moving position of the movable unit, and sets the volume or other parameter based on the detected position.
Generally, the movable unit is adapted for movement in the box body longitudinally thereof by being guided by a round bar or other movement guide which is disposed in and longitudinally of the box body.
Also known is a slide operation apparatus capable of adjusting a sliding resistance between the movable unit and the movement guide during movement of the movable unit (Japanese Laid-open Patent Publication No. 2002-8907). This slide operation apparatus includes a squared U-shaped spring disposed to sandwich the movement guide with a sandwiching force appropriately settable by a screw, whereby the sliding resistance (sliding frictional force) can be adjusted.
As described above, however, the slide operation apparatus disclosed in Japanese Laid-open Patent Publication No. 2002-8907 requires the provision of the U-shaped spring and the screw for friction generation, resulting in a complicated construction of the friction generating mechanism, which poses a problem. Another problem is that the friction generating mechanism is not easy to assemble because the U-shaped spring must be mounted such as to sandwich the movement guide, and the screw must be attached.
In recent years, a slide operation apparatus has been known that does not include a brush-type detection device but includes a magnetic detection device or other non-contact detection device for position detection of the movable unit (Japanese Laid-open Patent Publication No. 2006-49302). This type of slide operation apparatus cannot utilize the sliding resistance between the movable unit and the position detection brush for the holding of the movable unit. As a result, the movable unit is freely movable and hence there is a fear that the movable unit is unintentionally moved such as being fallen from its original location depending on the mounting angle of the movable unit relative to the apparatus. To obviate this, the above described friction generating mechanism or other mechanism must be additionally provided to thereby apply an appropriate sliding resistance to the movable unit during the movement thereof.
The movable unit of the slide operation apparatus disclosed in Japanese Laid-open Patent Publication No. 2006-49302 includes a position sensor adapted to output a signal representing the position of the movable unit. A flexible flat cable for transmission of the detected signal is extended from the movable unit to the outside of the apparatus via a guide through hole formed in a housing of the apparatus. This type of slide operation apparatus includes a ground line through which is discharged a high voltage, if any, applied from the operating element operated by a user charged with static electricity.
Recently, a mixer or other signal processing system mounted with a plurality of slide operation apparatuses has been demanded to have a “touch sense function” to permit the mixer or other system to recognize which one of the slide operation apparatuses is currently operated. With the touch sense function, a channel in the mixer corresponding to one of the slide operation apparatuses which is currently operated or manipulated by a user is made active, or the data rewriting is enabled upon operation of the apparatus, for example. To realize the touch sense function, a ham noise detection line, for example, is provided in each of the slide operation apparatuses. The ham noise detection line is at the same electrical potential as the operating element of the slide operation apparatus, and is ungrounded. Upon detection of ham noise generated in the ham noise detection line when the user touches the operating element of any of the slide operation apparatuses, the touching to the currently operated operating element is detected.
On the other hand, however, the operating elements cannot electrically be grounded in order to achieve the touch sense function. In that case, when the user charged with high-voltage static electricity touches any of the operating elements, the slide operation apparatus can erroneously operate or become faulty, which poses a problem.